"DETROIT -- A U.S. government safety agency wants electric and hybrid vehicles to make more noise when traveling at low speeds so pedestrians can hear them coming."

"The cars and trucks, which are far quieter than conventional gasoline or diesel-powered vehicles, don't make enough noise at low speeds to warn walkers, bicyclists and the visually impaired, the National Highway Traffic Safety Administration said Monday in a statement.

The proposed rule would require the cars to make additional noise at speeds under 18 miles per hour (29 kph). NHTSA says the cars make enough noise to be heard at higher speeds."